Moderator D2O Intermediate Storage Options Assessment after Final Shutdown
An evaluation grid was developed to facilitate strategic recommendations for the continuation of the project.
The highly tritiated moderator heavy water at the power plant is currently stored in the stainless steel tanks 3811-TK1 to TK4 in S2-001 (service building). This project consisted of assessing multiple options for 40 years storage of the highly tritiated moderator heavy water or to dispose of it off-site immediately.
Four options are evaluated and compared in this assessment:
- Storage in their existing (inaugural) stainless steel tank 3811-TK1 to TK4 in room S2-001
- storage in the high pressure emergency core cooling (ECC HP) storage tanks located in the turbine building T2-131
- construct a new building specifically designed for D2O storage
- provide a third party turnkey solution consisting of extracting the tritium to profit from the high commercial value of heavy water or recycle it in an operating plant
Numerous evaluation criteria are used for the four options presented:
- Radiological surveillance.
- long term waste inventory management (chemical stability)
seismicity of storage
- storage ambient condition requirements
- risk management (spills and vapor confinement/collection)
- efforts required for D2O handling
- impacts on decommissioning of various systems
- specific site protection requirements
- impacts on deconstruction of the plant
- regulatory authorisations
- social acceptability
- anticipated costs, including operating and maintenance.